Method of making bushings from strip metal



Aug. 29, 1933. J. H. DAvl's- 1,924,230

METHOD OF MAKING BUSHINGS FRQM STRIP METAL Filed Jan. 14. y19:52 2Sheets-Sheet 2 I Vfl {fg- (JH/WMO@ x Patented A ug. 29, 1 933 UMH-:DrsTATlv-:s

METHOD OF MAKING BUSHINGS FROM STRIP METAL James Il. Davis, Dayton,Ohio, assignor to Moi rainc Products Company, Dayton, Ohio, aCorporation of Ohio Application January 14, 1932. Serial No. 586,509

4 Claims.

This invention relates to an improved method of rolling cylindricalforms from a strip of sheet metal stock while maintaining the blankintegrally connected to the strip until the final forming 5 operationupon said blank.

An object of this invention is to provide such a method wherein thebushings formed thereby will have Acharnfered or otherwise finished endswhich require no further trimming.

Patent No. 1,787,255 Klocke, issued December 30, 1930, discloses amethod of forming bushings while maintaining the blanks integrallyunited with the sheet stock until the last forming operaation. Thispresent invention has an important advantage over the method of thisKlocke patent in the above-mentioned production of bushings withchamfered ends which require no further trimming, such as will benecessary in bushings formed by the Klocke method.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings, wherein ya preferred embodiment of one form of the presentinvention is clearly shown.

In the drawings:

Fig. 1 is a strip of sheet metal stock from which bearing bushings maybe formed by this invention.

Fig. 2 is a sectional view of the sheet stock and shows how the bearingblanks are successively partially cut from the main strip by theV-,shaped groove-forming dies.

Fig. 3 is a plan of the strip sheet showing the V-shaped groovesextending uniformly the full width of the strip.

Figs. 4, 5, 6 and 7 are transverse sections taken on lines 4 4, 5 5, 66, and 7-7 of Fig. 8, respectively.

4 Fig. 4 shows a section through the dies for shearing off the ends ofthe bushing blank tol 'sion of bushings to be formed. This metal stripl0 passes continuously over the lower die shown 65 in Fig. 9. The llatportion 11 of the lower die has a raised V-shaped wedge portion 12 whichis directly aligned with a similar shaped reciprocating upper die 13. Ateach stroke of the press the die 13 descends and presses smooth V-shaped70 grooves 14 and 15 in the upper and lower surfaces of the strip 10.These. grooves mark o ll the bushing blanks 16 but leaves them joined together throughout the full width of strip 10 by a relatively easilybroken connecting web 17 (see Figs. 2 and 3). The grooved metal stripthen advances over the portion 17 of the lower die `and at this stationthe upper reciprocating die 18 descends and ytrims off the'ends of eachblank 16 to exact dimensions (see Fig. 4).

The strip then advances until the trimmed blank is in position over theportion 2l of the lowerdie and at this station the reciprocating upperdie 22 descends and -gives the blank its initial forming as clearlyshown at 20 in Fig. 5. When the ends of blank 20 are curled downwardlyas shown, the connecting web 17 is easily progressively sheared orbroken free from the next adjacent blank since this web 17 is quitethin.

The partially formed blank 20 next passes over the lower die portion 25and at this station the reciprocating upper die 26 descends and formsthe blank 20 into the open channel form 27 clearly shown in Fig. 6.During this forming operation the connecting web 17 is sheared olf for afurther distance from both ends of the blank as will be readilyunderstood from the drawings, but still leaving the channel form 27integrally connected to the strip by a short length 28 of the web 17which will be suilicient to 100 properly guide and support the channelform 27 as it is moved to its next station. l

The next and nal forming station is shown in Fig. 7. Here the channelform 27 has advanced to a position over the circular mandrel 30and 10the upper and lower dies 31 and 32 have formed it into the circularbushing 35. At the time of this nal forming the connecting web 17 is`com-` pletely severed by the shearing action of the upper reciprocatingdie 31 and hence the formed 110 bushing 35 will drop from the end ofmandrel 30 when the dies 31 and 32 recede and it is pushed endwisetherefrom by the next advance of the succeeding channel form 27. Thiscomplete severance of web 17 is preferably made more positive or certainby providing a small drop or shoulder 40 (see Fig. 9) between the uppersurfaces of die portion 25 and circular mandrel 30. The descent of die31 will then obviously completely and positively sever the lastremaining short length of the connecting web 17.

It is to be noted that the original V-grooves 14 and l5 form smoothbur-less chamfered end surfaces to the formed bushing 35 and hence nofurther trimming of the ends of the bushing 35 will be necessary. Bythis means the usual chamfering or other trimming or finishingoperations on the ends of the bushings is entirely obviated and therebythe cost of manufacture is greatly reduced.

I have shown and described only one method of forming the transverselygrooved strip into circular bushings for illustrative purposes.Obviously this invention is not limited to the specic number of formingstations or to the particular shapes of forming dies shown and describedherein, as these may be greatly varied by those skilled in the art. Anessential feature of the method of this invention is the step ofpressing the transverse grooves in the strip stock and leaving arelatively weak connect-ing web between the blanks so that the finallyformedr bushings will have chamfered or smooth finished ends such aswill require no further trimming.

While the form of embodiment of the present invention as hereindisclosed, constitutes a preferred form, it is to be understood thatother forms might be adopted, all coming within the scope of the claimswhich follow.

What is claimed is as follows:

1. In a method of making bearings, the steps comprising: marking off abearing blank from a strip of sheet metal by a transverse grooveextending only partly through the thickness of said blank, then curlingthe ends of said blank in progressive curling operations to form abushing therefrom, said blank being, progressively sheared from saidstrip along said transverse groove by said progressive curlingoperations.

2. In a method of making bearings, the steps comprising: marking oi abearing blank from a strip of sheet metal by opposed transverse groovesextending only partly through the metal thickness thus leaving aninterconnecting web between said blank and strip, then forming saidblank into circular form by progressively curling the two ends of saidblank and simultaneously progressively severing said web of metal assaid blank is shaped to circular form.

3. In a method of making bearings, the steps comprising: marking off abearing blank from a strip of sheet metal by a transverse grooveextending only partly through the thickness of said blank, forming saidblank by transversely bending same into channel form and simultaneouslyprogressively shearing said blank from said strip due to such bending,then severing said channel form from said strip and forming same into aclosed circular bushing.

4. In a method of making bearings, the steps comprising: partiallydividing a bearing blank from a strip of sheet stock by pressingV-shaped grooves into the metal but leaving a relatively easily severedconnecting web between said blank and strip of stock, forming said blankinto circular form by progressively curling the two end portions of saidblank and simultaneously progressively shearing said connecting web bysaid progressive curling of said blank end portions.

JAMES H. DAVIS.

